1. Technical Field
The present invention relates to a light-emitting device and an electronic apparatus.
2. Related Art
In recent years, light-emitting devices have been widely used in display devices and electrophotographic image forming apparatuses as exposure devices. A light-emitting device includes a light-emitting element, such as an organic EL element (organic electroluminescence elements).
In a light-emitting device, durability against long-term light-emission is demanded, and dark spots lead to deterioration of the light-emission characteristics of the organic EL element. Dark spots are generated when water adhering to the surface of each of the constituent parts of an organic EL element, water (moisture) having permeated the organic EL element, or atmosphere gas, such as oxygen, permeates a laminate having a transparent electrode, a light-emitting layer (organic layer), and a rear electrode sequentially laminated through defect in the surface of the rear electrode, and disconnection occurs between the organic layer and the rear electrode.
For such a light-emitting device, in order to achieve an improvement in reliability and long lifespan for the organic EL element and, it is important to make the light-emitting layer or the electrodes constituting the organic EL element be reliably isolated from the atmosphere gas. For this purpose, a known technology is used to bond a substrate (transparent substrate) having an organic EL element formed thereon and a sealing member as a single body using an adhesive, to thereby protect the sealed organic EL element from the atmosphere gas. In order to suppress permeation of water as much as possible and prevent the light-emitting element from being deteriorated (sealing performance), the adhesive is preferably applied over a large width (seal area). In general, the seal performance increases in proportion to the width of the region in which the adhesive is applied.
For example, a light-emitting device disclosed in JP-A-2002-8855 is known in which a transparent electrode made of ITO serving as an anode, an organic layer made of an organic compound having at least a light-emitting layer, and a non-transmissive rear electrode made of aluminum (Al) serving as a cathode are sequentially laminated on a substrate made of a glass material, thereby forming a laminate. In addition, a concave sealing member made of a glass material is provided on the substrate in an airtight manner by applying an adhesive to cover the laminate, and an absorbent is provided on a surface of the sealing member facing the laminate. The absorbent is made of a compound, which chemically absorbs water and maintains a solid state even when water is absorbed.
In recent years, as shown in FIG. 21, as typified by a display panel of a mobile phone, a frame region 300 (a region excluding a display region 302 corresponding to a surface on which a light-emitting element 303 is to be provided) needs to be provided so as to be as narrow as possible. However, in order to provide a narrow frame, it is necessary to reduce the width of a seal region 306 where a sealing member 304 is provided. If the seal region 306 becomes too narrow, the sealing performance is deteriorated. That is, it is difficult to provide a narrow frame while ensuring adequate sealing performance. The sealing member 304 contains a gap material (silica, plastic, or the like) 314 so as to maintain a gap 312 between a sealing substrate 308 and a substrate 310 constant. Furthermore, in order to increase a moisture-proof property or to control the elastic modulus of the sealing member 304 to thereby increase workability, the sealing member 304 contains a filler (silica or the like) 316. Accordingly, when the sealing substrate 308 and the substrate 310 are bonded to each other, pressure is applied. In this case, when the sealing member 304 is coated on a multilayer wiring region 322 where a plurality of wiring lines 320 are laminated, leakages or short-circuits may occur between the wiring lines 320 due to the gap material 314 or the filler 316. Meanwhile, when the sealing member 304 is coated on a switching element region 326 where a switching element 324 is provided, the switching element 324 may not normally function, and the characteristics may be deteriorated. For this reason, it is necessary to separately arrange the seal region 306 so as not to overlap the display region 302, the multilayer wiring region 322, and the switching element region 326.